Helicopter and airplane sustained aircraft



April 20, 1948.

e. H.'Bow1 us HELICOPTER AND AIRPLANE SUSTAINED AIRCRAFT Filed June 12,-1945 2 Sheets-Sheet 1 INVENTOR. GLENN H. BOWLUS ATTORNEY April 20, 1948.G. H. BOWLUS 2,440,003

HELICOPTER AND AIRPLANE SUSTAINED AIRCRAFT Filed June 12', 1945 2Sheets-Sheet 2 INVENTOR. GLENN H. BOWLUS ATTORNEY Patented Apr. 20, 1948UNITED STATES PATENT OFFICE Glenn H. Bowlus, San Marino, Calif.

Application June 12, 1945, Serial No. 599,047

Claims.

This invention relates to aircraft and has as its general object toprovide anaircraft having the maneuverability of a helicopter and havinghorizontal flight characteristics comparable to those of a fastairplane. i

Another object of the invention is to provide an aircraft which in rapidhorizontal flight has a minimum of drag resistance and therefore amaximum of speed for a rotor propelled aircraft.

Another object of the invention is to provide an aircraft having a rotoror a plurality of rotors adapted in taking off and landing operations tofunction as sustaining rotors of the helicopter type and, in horizontalflight to function both as sustaining airfoil surfaces and aspropellers.

Another object is to provide-an aircraft including a central bodysection for carrying passengers, cargo, etc., which central body sectionis adapted to maintain at all times a substantially horizontal positionand including power driven rotors shift able from positions wherein theyfunction as sustaining helicopter rotors, to positions coaxial withtheecentral fuselage section, in which positions they function forhorizontal propulsion of th craft through the air.

A further object of the invention is to provide an aircraft such as thatindicated above, including rotor units located both fore and aft of thecentral body section and drive mechanism from a power plant to suchrotor units, adapted to transmit the drive in any of the severalrelative positions of the central body section and the rotor sections. V

Another object is to provide an aircraft-of the type indicated above,including novel landing 35 gear mechanism, adaptedto permit the landingof the craft with the two rotors disposed on their vertical, helicopteraxes. It is further contemplated that such landing gear shall be of acastering type which permits the craft to land helicopter fashionwithout being damaged by lateral movement caused by cross currents ofair.

Further objects and advantages of the invention will be brought out inthe following part of the specification.

Referring to the drawings which are for illus trative purposes only, r

Fig. 1 is a longitudinal sectional view through 2 taken as indicated bythe line 33 of Fig. 1, the body and landing gear being omitted;

Fig. 4 is an inverted plan view of the craft with the parts thereofillustrated in their positions for horizontal flight; and

Fig. 5 is a side elevation of the craft in the horizontal flyingposition.

As an example of one form in which the invention'may be embodied, I haveshown in the drawings an aircraft embodying a central fuselage sectionwhich is indicated generally by the reference character In, a head rotorsection indicated generally at I and a tail rotor section indicatedgenerally at |2. The head rotor and tail rotor sections II, and I2 arehinged to the central fuselage section III on horizontal transverse axesindicated respectivelyat 3 and M. This permits thetwo rotor sections tomove from the positions shown in Fig. 1, wherein their longitudinalaxes, indicated generally at 5 and Hi-ar vertical, to positions whereintheir longitudinal axes l5 and I5 are in aligmnent with the longitudinalaxis of the central fuselage section I0, indicated at I1, as shown inFig. 5.

The head rotor section II comprises a fuselage section l8 housing anengine I9, a nose portion 20 connected to the fuselage section l8 by asleeve 2|, and an annular shoulder wall 22 which joints the base of thesleeve 2| to the fuselage wall it.

Also, joined tothe sleeve 2|, by means of a series 10f radial spiderarms 23, is a ring 24. Journaled between the ring 24 and the pluralityof bearings 25, carried by the sleeve 2|, are a plurality ofplanetshafts 26. Secured on theshaft 26are, a series of planet pinions21 which mesh with crown gears 28 and 29 formed respectively on rotorhubs 30 and 3|. Bearings 32 and 33 are interposed between the shoulderwall 22 and hub 3|] andbetween the hub 3| and nose 0 member 20respectively. The planet pinions 21 serve to transmit drive to the rotorhubs 30 and 3| are formedintegrally with rollers 21' which roliuponbearing surfaces 28' and 29" on the hub rings 30am! 3| respectivelyfor'rollingly trans mitting axialthrust between the two rotor hubs.Mounted in the-hubs 30 and 3| are a series of propeller blades .35 and34 respectively. Each blade has a. shank indicated in dotted lines at36, journaled in a, respective bearing 31 in its rean aircraft embodyingthe invention, with the .spective hub, Thus there is provided a pivotalrotor section shown in'the landing and take off positions;

Fig. 2 is a transverse sectionalview of the same taken on the line 22 ofFig. 1;

Fig. 3 is a planview of the head rotor nit' w and-the inventioncontemplates the use of conventional mechanism for making such pitchadjustments. Since a conventional adjusting mechthe fuselage to form apair of semicircular cars 66 by means of which the central fuselagesection H3 is joined to the head rotor section I l on the hinge axis l3.The lower extremities of the wall portions 64 are joined by a floor wall61 and cooperate therewith to define a pilots compartment. The floorwall 61 includes a movable portion 61' hinged at 61. so that, it may beswung downwardly to provideaccess tothe pilots compartment. The

engine crank shaft and a beveled gear 4| (mesh? ing with the gearmounted on a shaft 26a forming one of the series of shafts-referred togerre orally at 26. It is to be noted that bevel gears! and M arelocated within the sleeve: Zl. The en? gine I9 is provided with atransmission l9"in eluding a free wheeling clutch for permittinstau--torotation of the rotors in the event of engine failure. Thetransmission l9 projects into the base" portion of the sleeve. 2'l*,,which base portion is flared in order to accommodate'thi's part oftheengine. From the shaft 26a; the drive istransmitted throughits planetpinion 21 to'the crown gears 28 and ZBres ectiVely Whichwillbe=-therebydriven in opposite directions The head rotor section II carriesapairbf-stub wing sections 42 disposed in aplane roughly par-- allel tothe axis l5. Hingedat-Nto=each-of"the wings 42 isazlanding'gearincluding a bracket 44-, a castoring. fork 45 and a wheelH5 mounted in' the fork 45 and projecting beyond the-trailing ex:-tremity of the headrotorzsection H seas to-sup-- port the latter abovearunway surface: The: hinge .43 is disposed at suchan angle thatthezlanding gear may fold; tqaposition encompassedv substantially within;the wing 42; In. order thatv this. may be accomplished, the-bracket and:wheel 56- are disposed withinan area: lying close? 13 adj acenta singleplane,- and when; the landing: gear is in retracted position, this-p1aneis-r0ugh 1y parallel and coincident with the plane ofthe wings 42;Y Y

The tail rotor section- [2: comprisesa: fuselage portion 41, a terminalportion flconnectedf t'o the fuselage portion 41 byawaist portion (l9;and a tailrotor which is indicated 'generally at? The" rotor 5S1includes; a hub: annulus 51 a pairroff blades 52 mounted in the hub-fil-f'or pitchradiust ment to any suitable conventional: adjustingmechanism. Thrust bearings: 53 iare= interposed between the hub 5|andthefuselage and termiirah portions 4! and-48 respectively:'llherotor-tnsis,

driven by a pinion 54meshingwith aniinternal;

ring 7 gear 55- formedin the hub 511 The: pinion: 541s mounted-one;shaft 56 which is journaledrin: 5-5

a bearing 51 carriedby the -end2wall758-of thestail: fuselage section41.

Mounted inthe terminal portion: 48:0f'2'thei=taili sectionis atail'wheel 59*whichscooperateszwithi the castor wheel 46insupporting-thecraft-.for; movement on a;runway.

The tail 'section lz also-includes aerudder: 60 carriedon a rudder shaftfi l -wli'ichz is -joumaid'. in abearing 6-2 in tlie tail -fuselagesection; 41 at substantially right angles; to the longitudin'al' axis i6thereof, and arranged to projectdownwardly and below the-fuselage of thecraft-when the-craft is arranged for horizontal flight-31S 'ShOWHlHTFlgI The central fuselage sectionlfl includesamain" body portion 63having: at: its; forward end; andnearthe top thereof, a pair ofiinsetwallportions; 64 which are joined to the-mainrlateral wall'ofi the bodysection.fi3' by offsetiwallszfi5zl Thar-wall:

offset walls 65 merge with a forward end wall 65 which joins the floorwall 61 to the lower extremity of the main lateral wall of the bodyportion arrangedv for vertical-1 helicopter action as shown in' Fig. 1..

The rear end of the centralzfuselage section It is a separate tubular:portion' Tilt-having a swivelin connection lflz' with theunain .body'section 63; wherebyithe portion. I01 may rotate, withreference totheportion 63.; about the axis ll. Suitable means (hotshown)islprovidedfor. effecting rotatingimovementiof afew'degreesto eitherside of a. neutral position; of the: tail' section l2 rela tive to; thecentral: fuselage: sectionl-B; in order to: providetbetter controlfor'hovering; purposesfor examplmit is possible; through-this control,tot shift therta'il portionof the craft horizontally about: thevertical: axis; ofi'g-yration of the craft asa'awholetIntiietoperatiorrofr the-craft, with theparts dis- DOSBdz as showniinE'ig; 1-, ,therotor-s 38, 39, andtfl, driven bytthe: engine; 19; will.act as helicopter IOt'OlSEtOrlift thei craft vertically fromthe: groundorpermit ititasettle gentlytothe-ground; When thus operating; the rotorshave their respective blades feathered to positions inl-which they havea:- relatively, small. angle of attack. in relation Y to theirgeneral;planesmf-rotation" This: provides for the highliftawhichisrequiredior helicopteractiom 4 r I After: the cra-tthas a-beenithuslifted to. a sufficient height the pilot operatesthe. controls togradually bring; theirotorsections toward'horizontal flight position,wherein their axes. are aligned with. the axis I] of. the centralfuselage section |0;.-as..shown.in-Eig. 5. At the sametime, the: pilottgradually changesithe angle of. attack Of-the-rOtor b1ades.untilthisangle approaches a right-angle. with reference. to the planes of therotation of. the-.- rotors. This. position of adjustment of.theblades,isshowninFig. 4' and in Fig 5.. Assuming now that thegradualltransition from the. helicopter'action to. horizontal flightaction .hasb'een completed 'and'that the parts are correlatedas shown inFig. Sj the rOtation of the rotors produce-sthe primary effectof-propellin the craft horizontally through theair by a high pitch airscrew action; and the secondary effect of providing sustentationthrouglrwing action of therotor bladese This -w ing action is comparableto the-lifting actionmf thetfixe'dr wings of: a' conventional airplane;in which lift/i5? produced by the action of the air currents against theairfoil' surfapesproducing;positive pressure beneath the wings andreduced: pressuremor suction against p j ts from the-end ofrthe bodyportlon ofa therupperzsurfacesofithe wings: Therotorwblades of flight,and consequently the rotor blades will have an average angle of attackwith reference to the line of flight, which will produce an aver-. ageor net lifting action. Analyzing this action in detail, it may be notedthat because of'the inclination of the blades with reference to theangle of flight, those blades which are moving downwardly will exert amore direct thrust against the body of air in which they advance thanthose blades which aremoving upwardly, and there will be a very definitelifting action resulting from the relative downward movement of theseblades against the body of air in which they are moving, while anytendency of the upwardly moving blades to react against the air abovethem and exert a downward push against the craft, will be minimizedbecause of the general inclination of the axis of the craft withreference to the line of flight. By employing twin rotors andcontra-rotating then1,the higher lift of one rotor on one side of thecraft is balancedagainst the higher lift of the other rotor on theotherside of the craft, thus giving stability around the longitudinal axis ofthe craft. It may be noted at this point also that the forward rotor issmaller in diameter than the rear rotor in order that both rotors mayexert the same effective pull against the air, the larger diameter ofthe rear rotor compensating for its decreased efliciency arising fromturbulence set up by the forward rotor. The larger diameter of the rearrotor of the head section also compensates for the effect of the singlerotor at the tail, which is relatively small. The tail rotor 52 isdriven from the shaft 26 through a bevel gear 72 on the shaft 26, abevel bear 13 on a shaft 14, a second bevel gear 15 on the shaft M,meshing with the bevel gear 16 journaled on one of the hinge studs I3, abevel gear Tl mounted on one end of a shaft (8, a universal joint 18a,connecting shaft 18 with a shaft 18b, a bevel gear 19 on the other endof the shaft 181), a bevel gear 89 journaled on the tail section hingeshaft M, a bevel gear 8! meshing with the bevel gear 80, and the shaft56 on which the bevel gear 8: is secured. V

The shaft M is journaled in bearings 82 on the sleeve 2| of the noseportion of the craft. The shaft 18 is located adjacent one side of thecentral body portion 63 of the fuselage l9, and is journaled in bearings83 attached to said central body portion. 7

It may now be noted that the drive which has just been described is anarticulated drive which permits the three sections of the craft to behinged relative to each other without interfering with such hingingmovement or having such hinging movement interfere with the drive.

From the shaft l9, power is taken to operate mechanism for shifting thebody sections relative to each other, such mechanism comprising a rockshaft 84 carrying a pair of cranks 85 and 86, a push-pull rod 3? pivotedto the crank 85 and to the body section I8, another push-pull rod 88pivoted to the crank 86 and to the tail section 41, a reduction gearunit 89 for driving the rock shaft 84, a friction disc 90 on the driveshaft 90a for the reduction gear unit 89, and a pair of friction rollers9| and 92 selectively engageable with the friction disc and carried by asleeve 93 which is splined to and slidable upon the shaft 18. The sleeve93 is shifted bya fork 94 engaging a collar 95 on one end of the sleeve93, the fork 94 being pivoted to the body section 63 at 96 and beingoperated by av push-pull rod 91 and a control lever 98 pivoted at 99 tothe body section 53, the rod 91 being linked to the lever 98 and to thefork 94.

An operator seat I00 is conveniently placed in the forward portion ofthe central body section of the fuselage, and an operator compartment isprovided for by -this forward portion of the body section 63 and by atransparent canopy ml which may be of plastic such as Plexiglas.

Control of the rudder 60 is provided for by a pair of rudder pedals I03,pivoted at l IM to the wall members 64, and a-pair of cables I05attached to the lower ends of the pedals I03, ex-

tending rearwardly through the fuselage and into the tail section,extending around pulleys (not shown) journaled on the shaft 14, andattached to a tiller bow .106, attached to the rudder post 6 l.

The stub wings 42 function for trimming the craft laterally, andtherefore are provided with ailerons 42' provided with conventionalmeans (not shown) for differentially adjusting their positions in themanner that ailerons are conventionally operated. a i

I claim as my invention:

1. In an aircraft, a main body section, nose and tail sections hingedto'the forward and rear ends thereof respectively on horizontal axes,the rear end of said main body section comprising a separate portionhaving a swiveling connection with said main body portion about thelongitudinal axis thereof, a rotor rotatably mounted on said nosesection and including blades adapted to be pitch adjusted from positionswherein they may function for helicopter type lifting to positionssubstantially at right angles to said first mentioned positions, whereinthey may function, with the axis of said nose section substantiallyhorizontal, as wing sustention and forward propulsion means, means fordriving said rotors, and control means for orienting said nose and tailsections from positions'with their longitudinal axes substantiallyvertical, wherein they are adapted to function for helicopter lifting,to positions wherein their axes are in substantial alignment with theaxis of the main body section, in which positions the craft is adaptedto fly horizontally.

2. In an aircraft, a central body section, nose and tail sections hingedupon horizontal axes to the forward and rear ends of said central bodysection respectively, rotors rotatably mounted on said nose and tailsections respectively, means for driving the nose section rotor,articulated drive transmission means for driving the tail rotor from thenose rotor, said transmission means including a shaft extendinglongitudinally through the central body section, drive elements centeredupon the hinge axes between said body sections, and connections betweensaid last mentioned drive elements and the respective rotors, and meansfor articulating said body sections with reference to each othercomprising a rock shaft transversely journaled in said central bodysection, a pair of crank arms mounted thereon and projecting in oppositedirections, means connecting said crank arms to the respective nose andtail sections, reduction gearing driving said rock shaft, and reversibledrive mechanism for driving a d eduction s a ing rpm a d on tud lyextending shaft.

3. I an a r af :8 ma n bed cti 995 ection and aia ls c ion hing d theren on h zontal axes of the forward'an d'rear endsthereof respectively,rotors rotatably mounted on said nose and tail sections respectively,means for articulating said sections from positions wherein said noseand tail sections have their longitudinal axes substantiall verticallydisposed and at'right angles to the longitudinal axis qf the centralbody section, in which positions said'rptors are adapted to function forhelicoptertype lifting, to positions wherein said axes are insubstantial alignment and e ssues horizontal, in which latterpositionsQsaid rotors are adapted to function for forwardpropulsion, a'rudder'car-ried by said tail section, retracted into the central bodysection when the tail section is upright and projected downwardlytherefrominto the slipstream thereof, when the tail section is' in'alignment with the central body section, andmeans for controlling saidrudder from an operatorsstation in said 'central body section.

4. Aircraft as defined in claim 3, wherein said control means comprisesrudder pedals, "cables extending from said pedals" around the axis ofhinging moveriient betwen said central body section and saidtail'seetion, arid tiller means connecting' said cables to said rudder.

5. In an aircraft, a central body section, nose and tail sections hingedthereto on horizontal axes at the forward arid rear ends thereofrespectively, rotors rotatably mounted on'said nose and tail sectionsrespectively; control means for articulating said sections frompositions wherein said nose and tail sections are disposed with theirlongitudinal axes' substantially vertical and at right angles to thelongitudinal axis o-f-the central body section, in which positions saidrotors are adapted to function for helicopter type lifting, "topositions wherein said axes are all in substantial alignment andrelatively horizontal, in which latter positions, said rotors areadapted to function for forward propulsion, with the forward rotor alsofunctioning for wine: susterition, means for driving said rotors,landing gear attached to'the free end of said tail section and to anextremity of'said nose'section which is lowermost when said nosesection' is in its upright position, and a rudder carried by said tailsection and retractible into the fuselage portion thereof when said tailsection is in its upright position.

' GLENN H. BOWIiUf-S.

REFERENCES CITE The following references are of record in the file ofthis patent: v

S A E A ENT-s Number Name Date 991,686 Alleas May 9,1911 1,414,241 Wells1 Apr. 25', 1922 1,794,202 Pickard Feb. 24,1981 1,833,722 Prokop Nov.24, 1931 1,846,992 Decker Feb. 23, 1932 1,875,257 SaVoia Au '30, 19321,951,817 Blount Mar. 20, 1934 2,043,704 McPherren June 9,1936 2,094,997cien Oct. 5, 1937 2,300,26 Stuart, 3rd Oct, 27, 1942 2,308,802 Barling"Jan. 19, 1943 2,332,4 0 Youn g' Aug. 14, 1945 FOREIGN PATENTS NumberCountry Date 810,054 France Dec. 19, 1936

